Tips / Secrets of the trade? What works for you?

[SiPMerlin150]

Just looking at images of other peoples methods of repair to vehicles, most notably replacement of sections that have rusted out, I would like to do half of a neat job that some people seem to manage.

I can weld relatively neat, stick two pieces together well enough, but my downfall is being able to cut things / fit things up neatly.

Take this for example, in this link (http://forum.difflock.com/viewtopic.php?p=224739&sid=bacddae3eba6b4771390f2756a5968f7)

Is it possible to get a cut that neat with an angle grinder? I have steady hands and i'd fail to acheive that

I have primitive hand tools, except for the welders, grinder, and drill. I have no air tools at home or no cover to work, so i'm out in the elements. I work with my tools spread out all over the drive and try my best to get things done.

When this weather (If, big if!) dries up I would like to do some repairs to my ageing car in prep for when I leave it to my youngest brother who will begin his driving lessons next year. (I'll be gone to land down under by then) I want the car to be structurally right for a good few years for him.

It needs some areas under the arches plating up, a small area on the jacking point at rear and maybe behind the front arch liners around the front chassis legs. (not gone through, but underseal peeled away showing lovely rust!)

Any tips for the cheap guy in the form of metal cutting/shaping fitting up etc?

 

[cumbriasteve]

Some find it easier than others and seem to have a natural flair for it, even though my apprenticeship was as a sheet metal worker I am often amazed at some of the metal forming so called amateurs achieve in their restorations.

Lots of bits of different angle, flat and round bar, along with clamps for shaping over always helps and working the metal in small stages, dealing with any distortion as it happens.

Cardboard templates that fit perfectly before cutting the steel is one of the biggest aids.

As for cutting old steel out, after years of doing the work I can get a very accurate cut with a normal grinder and very thin blade, for someone just starting up I always suggest something lighter like a Dremmel with a small cutting disc.

When using either then being in a comfortable position, ideally resting your arm against something or you will wander all over the place, actually very similar to how you achieve a steady hand when welding, protective gear to prevent jumping from hot sparks and a really good light on the area helps too.

There are some good youtube clips regarding this type of work

 

[Angusdog]

Is it possible to get a cut that neat with an angle grinder?

Yup. I'm no expert but with a 0.8mm disk on a 115mm grinder, it's pretty easy. What size are your disks and grinder? Thick disks or a huge grinder does make things much harder. I can manage some pretty delicate work with my grinders (I have one with a cutting disk and one with a flap wheel usually). Having something to rest your arms against helps hugely.

I can empathise with working in the driveway - my garage is not big but I still end up cutting and welding in the driveway sometimes. I'm into minis because they're cheap and small - my budget and space couldn't run to much more to be honest.

Thinking before cutting, cardboard templates and patience will be your friends here. It's not rocket science but equally first attempts tend to be laughable. Your next will be neater and build on that.

 

[Drains]

The order you mark and cut can help. It can be easiest to cut away the crud on the body, then make the fill in piece slightly oversize, offer it up to the bodywork and mark around, then cut more away from the bodywork to fit the fill piece, rather than making the fill piece fit the hole. Even better if you're joggling as you then have an accurate mark to joggle to.

By doing it as above you don't need to keep cutting and checking (and inevitably overdoing the cuts), as you may if you're trying to get a piece of sheet to fit a hole.

 

[mike 109444]

A "SOLID" work surface is a must. As you may not have the room under cover then think about a tree stump/log 3' tall and say 1' dia make a stand for it, failing that then an rsj or length of rail track. You need something that you can beat metal on that won't shake to pieces. If you have not seen this http://retrorides.proboards.com/index.cgi?board=usetharch&action=display&thread=70135 Then it's worth an hour or two of reading!
Cardboard templates are good (use myself) but remember steel does not bend as easy as card and so allow extra when cutting template in steel from card outline.
Learn handtool shrinking and streching (still trying to get the hang of this)
Ref the weather the weatherman on radio 4 said the rain will move away to be replaced by showers!!!

 

[Sean]

a sharp scribe, scribe round the patch youv'e made and buff back to the line with something like 80 grit flap wheel and a hand file for the corners.

Sean

 

[cumbriasteve]

A "SOLID" work surface is a must.:

Yes I forgot that bit of valuable info..nothing worse than trying to shape steel over something thats weak or moving about.

A trip to the local scrappie is often worthwhile, a small length of rsj or old railway line with a flat surface is well worth getting....if you manage a hernia picking it up then it's about the right weight.

I got 600mm of H girder for a fiver, great for clamping to, flattening bar, centre punching on etc etc and it's probably been used more than anything else I own.

 

[SiPMerlin150]

My grinder is a small 115mm disc unit, the cutting disks are 2.5mm thick, (cheapies from B&Q) I find them a little slow on thicker metal, but they last compared to a 1mm Dronco disk that cust fast, but disapeared before my eyes.

You're right on with the first attempts! I frequently used to cut the new pieces in to shape, have them overlap the hole to be welded by an inch of good metal, tack it into place, and tapping it into position/shaping it as I went along. That only normally works when theres a good back up of metal behind the repair (hence the need for an overlap of an inch all round) Otherwise you tend to have the new piece becoming bowled in rather than be level. I want to do it properly now though

 

[SiPMerlin150]

As for shaping, I've normally used the edges of a block of wood or even the solid stone step of the shed to shape the steel sheet in prep of the repair, Its all rough handed so its my own fault really for not using the measure twice, cut once theory

Boy oh boy I still have so much to learn..

 

[gavuk]

You are making life difficult if you use 2.5mm cutting discs on bodywork,use 1mm or thinner discs and don't force them,i normally score the line to be cut using the disc then cut right through....

 

[Luke]

1mm disks, used gently, last ages. Side pressure or twist can make them wear quickly or at worst shatter. If they don't last its likely you're giving them too much stick. Have a look at rightlines.co.uk for bulk buy disks.

 

[SiPMerlin150]

I am rather heavy handed on tools, I do push down on the cutting disks so this could be why they don't last. 1 dronco disc saw me around 24 inches approx of cutting 3mm & 4mm steel... Thats not much is it?



What tools do you suggest for scoring cutting/folding lines?

 

[Lawnmowerboy]

Don't let it cut all the way through just score at it. If you cut all the way through you're letting the disc rub which makes them get hot and start to smoke.

 

[Sean]

I am rather heavy handed on tools, I do push down on the cutting disks so this could be why they don't last. 1 dronco disc saw me around 24 inches approx of cutting 3mm & 4mm steel... Thats not much is it?



What tools do you suggest for scoring cutting/folding lines?

take your pick!

also a selection of marker pens, pencils and chalk/soapstone get used

 

[SiPMerlin150]

take your pick!

also a selection of marker pens, pencils and chalk/soapstone get used

Cool! buying the carbide tip pen scriber, I can make good use of that, thank you

 

[slimjim]

I hardly ever use a grinder to cut metal,

If they are just small patches, I use hand powered monodex cutter, having first drilled some holes, to do the patch I either use cardboard template, or cut a patch slightly larger and trim down using aviation snips piece by piece, if its a large piece that needs cut out, I will reach for the plasma, most patches can be formed with a couple of blocks of wood, a blunt chisel, a few bits of thick walled pipe, and a 6 inch vice, can't remember the last time I joddled a patch to fit over, if there is a gap I use some copper pipe to back the joint so I can fill any gaps, but if access is not available, I use my portamig on the second lowest setting which enables me to weld a bead on the edge of the patch building it up enough to fuse between the gap, using a couple of goes if necessary, it can sometimes be necessary to hammer the new patch so it's slightly below surface level, then a skim of filler hides the join, this is preferable to grinding it flat, which can leave the metal to thin,

A useful tool is a hand operated shrinker stretcher, a bossing hammer and leather sand bag

 

[1192simon]

secrets of the trade ? What works for you

Mate , you are on the right track and have received alot of good information. 2.5mm discs are a waste of time for precision. My lads go through abouth 75 1.0 mm discs every wek in theyre stainless stair installations , but the angles are allways right and this enables the weld to be sanded and polished efficiently. Your biggest block will be to just take your time and measure and mark things 2 or 3 times if necessary. It will save you a shed load of work in the long run. I used to be a rusher myself and never got anywhere. Just take your time my friend and good luck . .... Si

 

[SiPMerlin150]

I've taken a lot of all this information in today and will put it to good use in the next job that comes along and beyond.

You're right on the 'rushing' part, its not that i'm wanting the job done quick and to be out of the way, I would just like to do these jobs at a more productive pace, as in the past i've spent a good 20/30 minutes attempting to fit up a patch, cutting, hammering, shaping etc.

I've purchased a scriber, and a new draper metal sheet hand monodex cutter, and going to purchase some thin cutting discs & some flap disks for the grinder.

My new years resolution is to do the job properly and thoroughly. I will not care if someone calls me a slow butt!

 

[RedOrZed]

I've taken a lot of all this information in today and will put it to good use in the next job that comes along and beyond.

You're right on the 'rushing' part, its not that i'm wanting the job done quick and to be out of the way, I would just like to do these jobs at a more productive pace, as in the past i've spent a good 20/30 minutes attempting to fit up a patch, cutting, hammering, shaping etc.

I've purchased a scriber, and a new draper metal sheet hand monodex cutter, and going to purchase some thin cutting discs & some flap disks for the grinder.

My new years resolution is to do the job properly and thoroughly. I will not care if someone calls me a slow butt!

I get what you say about the work taking a long time, it's when you think "WTF it's taken two days to do this", the thing is that when it's not your day job (certainly not for me!) then it really is going to cost you a lot of time, compared to a professional. OTOH, how much money would a professional charge, and how much time and effort would it take you to get the job to them??

I find it a bit frustrating that I'm not quicker, but it's a great feeling doing the work yourself, knowing exactly what's been done and that it's done to a standard I'm happy with, even if the actual part of the job is a small percentage of it

I've never had my welding called into question by an MOT tester and even had one praise it

 

[zardoz]

I did a couple of similar "invisible repairs" on my sill. The key word in that sentence is 'my'. Because it was my own vehicle, I could spend a lot more time on it without worrying about charging the customer, and the face he was going to pull when I told him I'd taken 3 FULL days to do it and would have to charge him accordingly.

Repairs done 'at work' are often priced first and the work fitted down to it afterwards (if you know what I mean)

Do a job for yourself and it doesn't matter how long you take as long as it is done to your satisfaction, and/or whatever standard you have pre decided on. The cost often being irrelevant. This is why on this forum we often see 'invisible' perfect or near perfect repairs done on classic cars owned by ourselves.